Underwater electrical connections



June 6, 1967 K. w. MCLCAD f 3,324,449

l UNDERWTER ELECTRCAL CONNECTIONS Filed June 19, 1964 United States Patent O 3,324,449 UNDERWATER ELECTRICAL CONNECTIONS Kenneth W. McLoad, Houston, Tex., assigner, by mesne assignments, to Schlumberger Technology Corporation, Houston, Tex., a corporation of Texas Filed June 19, 1964, Ser. No. 376,535 7 Claims. (Cl. 339-117) This invention relates to underwater electrical connections and, more particularly, to a method of and apparatus for making a connection between members under water, which -connection will be resistant to the adverse effects of water upon the connecting members.

Frequently, it is desirable to make a connection and particularly an electrical connection under water as, for example, by a diver or robot mechanism. Sin-ce much of the present day exploration and drillin-g for oil takes place under water, there are many applications for such underwater electrical connections. One such application involves the use of an electro-hydraulic valve system on underwater wellhead assemblies. Such an underwater wellhead is described in the Dec. 31, 1962, issue of Oil & Gas Journal, pages 140-142. The use of underwater Wellhead assemblies permits the completion of a well to be made under water so that no portion of the wellhead assembly projects above the water line but rather is positioned on the ocean floor. Additionally, it has been Vfound desirable to use positively acting electrical control equipment to manipulate valves, etc. on the wellhead assembly positioned on the ocean floor. It will, therefore, be necessary at times to install or replace electrical lines and connections at the wellhead under the Water.

One of the dificulties encountered in making such underwater electrical connections is the presence of sea Water in and around the parts of the connector, which parts are extremely vulnerable to destruction by electrolysis between connector parts operating at appreciable potential differences. Such electrolysis between the parts will cause erosion of the connector thus rendering it inoperable so that it must be replaced. Replacing such underwater connections can be very expensive.

It is therefore an object of the present invention to provide a method of and apparatus for making an underwater electrical connection substantially free from the effects of water upon connecting members.

Another object of the present invention is to provide a method of and apparatus for making an underwater electrical connection wherein sea water entrapped in the connection during the connecting of members is purged and replaced by a more suitable medium.

Still another object of the present invention is to provide a method of and apparatus for making an electrical connection which may be purged of sea water therein and refilled with an insulating fluid.

With these and Lother objects in View the present invention includes a method and apparatus for making a connection underwater wherein the connector housing has means thereon for purging sea water entrapped in the connection from the connector housing and replacing same with a dielectric uid. More particularly, the apparatus includes a pair of connector housings having mutually engaging connectors therein and which housings have detachable means thereon for making a fluid-tight coupling between the housings. Inlet and outlet ports on one of the housings provide a means for introducing water-attracting and dielectric fluids into the housing and for discharging uids from the housing.

The method of making an underwater connection with this apparatus includes joining the connector members under water and thus entrapping a quantity of sea water within the connection. A lluid supply and discharge means ice are then connected to the inlet and outlet ports on the connector housing and a water-attracting fluid is pumped into the conne-ctor housing to displace sea water therein from the housing through the discharge means. The uid discharging from the connector housing is continuously tested to determine the salinity of the water thereby to derive an indication when the connector has been purged of water. Finally, an insulating fluid is pumped through the supply means into the connector to displace the waterattracting fluid and to provide an insulating. fluid medium about the electrical connectors. Fittings that connect the inlet and outlet ports to the supply and `discharge means are so constructed that they may be closed while the displacing fluid is flowing thereby permitting the insulating fluid in the connector housing to remain under pressure.

A complete understanding of this invention may be had by reference to the following detailed description when read in conjunction with the accompanying drawings wherein a connector embodying the present invention is shown with means attached thereto for performing the method of making the underwater connection.

Referring to FIG. 1 of the drawings, a pair of connector housings or closures 21 and 22 are shown detachably coupled to one another by a threaded collar 23. The collar 23 has a shoulder portion 24 formed thereon which overlaps an outwardly extending annular shoulder 26 on one end of the -connector housing 2. O-ring seals 27 are provided in grooves formed in a recessed bore portion 26a in ths housing 22 to form a fluid-tight coupling between the recessed bore 26a on housing 22 and a complementarily shaped shoulder portion 25 formed on the end of connector housing 21.

A pair of socket-type connector members 31 are shown extending from the connector housing 21. These connector members 31 are insulated from the housing by an insulating bushing 32 made of a iluorocarbon compound, glass, or other suitable material with substantially zero moisture absorption. This bushing also forms a fluid-tight seal between the c-onnector members and the housing. The connector members are made of a metallic, sea water resistant material such as Monel metal, titanium or cupronickel.

Connector housing 22 likewise has positioned therein plug-type connector members 33 which extend axially Within a bore 34 formed within the connector housing. The connector members 33 are arranged to be aligned with the socket-type connectors 31 on connector housing 21 so that when the two connector housings are coupled to one another, the connector plug and socket members are engaged to provide a plurality of electrical contacts, as shown in the drawing. The plug-type connectors 33 are likewise insulated from the connector housing by insulating bushings 36 which also form a fluid-tight seal between the connectors and the housing.

The non-engaging end 37 of each socket-type connector 31 extends into an axial bore 38 within the connector housing 21, with the ends 37 of the connector members being threaded to receive appropriate electrical connections which may be made to Ian electrically operable apparatus. The plug-type connector members 33, on the other hand, are suitably Vattached as by soldering to individual conductors 39 forming a part of a sea water resistant cable 41. An enlarged end 40 of the cable is bonded to the connector within a recess 42 formed in the end of the connector housing 22. A partition member 43 is provided Within lhousing 22 to separate the bore 34 and recess 42. This partition member also serves to support the plug-type connectors 33 `axially within the bore 34.

When the connector housings are coupled, as shown in FIG. 1, with the collar 23 tightened about the threaded end of the housing 21, the seal rings 27 positioned between thel intertting ends of the housings 21 and 22 form a fluid-tight seal between the housing members. This seal forms `a fluid-tight chambers() within the housings for purposes to be hereinafter described.

A fitting 51 is threadedly positioned within the wall of the housing 22 to provide an inlet port to the chamber 50 formed within the coupled housings. Another fitting 52 is provided in Ithe wall o-f the same connector housing 22 to provide an outlet port -to the chamber 50. A supply line in the form of a tube or hose 56 is connected to the inlet port while a similar `discharge means S8 is connected to the outlet port. The supply line which is connected at the one end to the inlet fitting 51 is connected at the other end to a reservoir 53 and pump 57 for pumping fluids in the reservoir through the hose and inlet S1 and into the chamber 50 formed by the connector housings. The reservoir 53 is divided into two sections, one for supplying a water-attracting fluid and ythe other for supplying an insulating fluid. Piping and valves are arranged so that the fluids may be supplied separately to the input end of the pump 57.

Hose 58- which is connected to fitting 52 extends to a reservoir 59 for receiving fluid displaced from the chamber within the connector housing through the outlet hose. A test device 61 is positioned in the hose or discharge line 58 and consists `of electrodes arranged to be immersed in the liquid flowing through the discharge line. A current is passed through these electrodes and a continuous measurement 'and record are made of the conductivity of the fluid.

A port, such as inlet and outlet ports 51 and 52, is shown in grea-ter detail in FIG. 2 and includes an opening extending through the wall of the housing 22. An enlarged portion 67 of the opening is threaded, A smaller passageway 67a connects with the enlarged portion 67 by means of a `smooth conical portion 66 which acts as a valve seat. A valve member 68 likewise has a threaded outer portion 69 for reception within the threaded portion 67. A flow port 72, extending lengthwise through the valve, `opens into a conically shaped end surface of the valve. The upper end 73 of the valve is sized to receive the lines 56 or 58 thereon. The lower end of the valve is conically shaped to fit the valve seat 66. Seal members in the valve end ensure a seal between the parts to render the valve uid tight. A handle 71 is provided on the upper end of the valve to provide means for rotating the valve. Rotation of the handle in one direction will shift the valve member 68 Within the opening to bring the conically shaped end of the valve member into contact with the conical portion or seat 66 to close the opening through the connector housing formed by passageway 67a and port 72. Rotation of the valve handle in a reverse direction will open the port to permit fluid flow.

In order to make an electrical connection underwater with the apparatus described above, the following procedure is used: the connector housings 21 and 22 are brought together as shown in the drawing with the recessed bore portion 26a on the end of housing 22 extending over the complementarily shaped shoulder 25 formed on housing 21 so that the O-ring seals 27 engage the shoulder 25 to provide afluid-tight connection between the connector housings. The collar member 231s threadedly connected to the housing 21 to render the connection secure and the interior of the housings fluid tight. During the connection of the housings 21 and 22, the plug and socket portions of the connector members have been brought into electrically contacting, interfitted engagernent with one another. It is readily seen that if the connection of the two housing members were made under water, water would have been trapped in the chamber 50 formed between the two housing members.

Next, the inlet and outlet fittings are connected respectively to the lines 56 and 58 shown extending from points at the surface where reservoirs 53` and 59 provide supply and discharge means for the system. Likewise, the pump 57 and test devi-ce 61 are positioned at the surface with the reservoirs. Next, the valves in ports 51 and 52 are opened by rotating the valves 68. A water-attracting fluid such as alcohol which is stored in one of the sections of the supply reservoir 53 is pumped through the supply hose 56 and inlet port 51 into the chamber 50 to the displace the water which has been entrapped within the chamber during the connection of the housings 21 and 22. The displaced water is forced out of the outlet fitting 52 and discharge hose S8 into the reservoir 59 shown attached to the end of the discharged hose. The test device 61 is operated in the discharge line to continuously test the conductivity of the discharged fluid and thereby `determine the salinity of the water. When all of the water has been displaced from the chamber between the connector housings, the conductivity will drop to a minimum level to indicate that the salt water has been displaced from the chamber 50.

At this point the pumping of the water-attracting or hydrophillic fluid into the chamber is discontinued and an insulating'or dielectric fluid such as a suitable type oil is then pumped in through the supply host to displace the water-attracting duid and thereby fill the chamber with the insulating fluid, which is allowed to remain in the chamber. The valves in ports 51 and 52 are constructed so that they may be closed while the insulating liuid is flowing through the chamber. This permits the insulating oil t-o remain under pressure in the chamber formed between the connector housings after the fittings are closed off. This pressuring of the insulating fluid irnpedes the entry of moisture into the chamber. It should be pointed out that this connector 4may be repeatedly engaged and disengaged so long as the method set forth above for purging the connector is repeated after each connection.

While a particular embodiment of the present invention has been shown and described it is apparent that changes and modifications may be made without departing from this invention in its broader aspects and therefore, the aim in the appended claims is to cover all su-ch changes and modifications as fall within the rtrue spirit and scope of this invention.

What is claimed is:

1. A method of making an underwater Aelectrical connection comprising the steps of: connecting electrical contact members together while submerged in water, enclosing the connected contact members in a fluid-tight chamber in which is trapped a quantity of water, and displacing the water trapped in the chamber with a substantially nonconducting fluid while said chamber remains submerged in water.

2. A method of making an under water connection comprising the steps of: connecting members together while submerged in water, enclosing the connected members in a fluid-tight chamber which enclosing traps a quantity of water in the fluidtight chamber, displacing the water trapped in the chamber with a water-attracting fluid, and displacing the water-attracting Huid in the chamber with a dielectric fluid.

3. A method of making an underwater connection between electrical conducting members positioned within closure means comprising the steps of: joining such conducting members while submerged in water and at the same time sealingly connecting the closure means within which the conducting members are positioned, displacing Water entrapped in the sealingly connected closure means with a water-attracting fluid, and displacing the water-V attracting fluid with an insulating fluid.

4. The method set forth in claim 3 and further including the step of continuously testing the displaced fluid to determine when the water has been purged from the sealingly connected closure means.

5. A method of making an underwater connection between electrical conductor members positioned within closure means comprising the steps of i joining such conductor members while at the same time sealingly connecting the closure means within which the conductor members are positioned, such closure means having inlet and outlet openings therein, connecting supply and discharge means respectively to inlet and outlet openings in the closure means, pumping a water-attracting uid through the supply means into the closure means to thereby displaced through the discharge means any water entrapped in the sealingly joined closure means, pumping an insulating iluid through the supply means into the closure means to displace the water-attracting lluid through the discharge means, and closing the supply and discharge means while pumping in the insulating uid to leave the insulating fluid under pressure in the closure means.

6. The method set forth in claim 5 and further including the step of continuously testing the fluid being displaced through the discharge means to determine the nature of the fluid occupying the closure means.

7. An apparatus for making connections under sea water comprising: rst and second housing members each having electrical connecting means therein and detachable connection means thereon for connecting said members together, said housing members arranged to form a fluid-tight chamber therebetween when connected together, corresponding ones of said electrical connecting means in the respective housing members being arranged to make contact when said housing members are connected together, and vertically and laterally spaced inlet and outlet fluid line-accommodating port means formed in said housing member for permitting fluid trapped in said chamber upon connection of said housing members to be displaced by another uid, said port means being spaced to insure effective displacement of fluid through said chamber, said electrical connecting means being made of sea water resistant, conductive material, and insulating bushings being positioned between said connecting means and said housing members, said insulating bushings being constructed of material having substantially no moisture absorption properties.

References Cited UNITED STATES PATENTS 484,543 10/1892 Pyke et al 174-14 1,548,733 8/1925 Moody 174-14 X 1,776,309 9/1930 Clark 174-14 2,094,692 10/1937 Hitz 137-15 2,341,058 2/1944 Paluev 174-14 X 2,857,557 10/1958 Imhof 317-9 2,894,054 7/1959` Cameron et al 174-21 3,010,747 11/1961 Bondon 287-116 FOREIGN PATENTS 502,504 3/ 1939 Great Britain.

MARVIN A. CHAMPION, Primary Examiner.

ALFRED S. TRASK, RICHARD E. MOORE,

Examiners. 

7. AN APPARATUS FOR MAKING CONNECTIONS UNDER SEA WATER COMPRISING: FIRST AND SECOND HOUSING MEMBERS EACH HAVING ELECTRICAL CONNECTING MEANS THEREIN AND DETACHABLE CONNECTION MEANS THEREON FOR CONNECTING SAID MEMBERS TOGETHER, SAID HOUSING MEMBERS ARRANGED TO FORM A FLUID-TIGHT CHAMBER THEREBETWEEN WHEN CONNECTED TOGETHER, CORRESPONDING ONES OF SAID ELECTRICAL CONNECTING MEANS IN THE RESPECTIVE HOUSING MEMBERS BEING ARRANGED TO MAKE CONTACT WHEN SAID HOUSING MEMBERS ARE CONNECTED TOGETHER, AND VERTICALLY AND LATERALLY SPACED INLET AND OUTLET FLUID LINE-ACCOMMODATING PORT MEANS FORMED IN SAID HOUSING MEMBER FOR PERMITTING FLUID TRAPPED IN SAID CHAMBER UPON CONNECTION OF SAID HOUSING MEMBERS TO BE DISPLACED BY ANOTHER FLUID, SAID PORT MEANS BEING SPACED TO INSURE EFFECTIVE DISPLACEMENT OF FLUID THROUGH SAID CHAMBER, SAID ELECTRICAL CONNECTING MEANS BEING MADE OF SEA WATER RESISTANT, CONDUCTIVE MATERIAL, AND INSULATING BUSHINGS BEING POSITIONED BETWEEN SAID CONNECTING MEANS AND SAID HOUSING MEMBERS, SAID INSULATING BUSHINGS BEING CONSTRUCTED OF MATERIAL HAVING SUBSTANTIALLY NO MOISTURE ABSORPTION PROPERTIES. 